Digital watermarking continues to proliferate. Watermarking has experienced success across many boundaries—including geographic boundaries. But sometimes boundaries need to be respected, e.g., in terms of content licenses (e.g., content may be licensed for use in one country but not another), laws and social rules, and even equipment manufacturers (e.g., some manufacturers may want certain types of watermark detection while other don't.).
We address geographic boundaries and geographic-based embedding and detection herein.
Digital watermarking—a form of steganography—is a process for modifying media content to embed a machine-readable code into the content. The content may be modified such that the embedded code is imperceptible or nearly imperceptible to the user, yet may be detected through an automated detection process. Most commonly, digital watermarking is applied to media such as images, audio signals, and video signals. However, it may also be applied to other types of data, including text documents (e.g., through line, word or character shifting, background texturing, etc.), software, multi-dimensional graphics models, and surface textures of objects.
Digital watermarking systems have two primary components: an embedding component that embeds the watermark in the media content, and a reading component that detects and reads the embedded watermark. The embedding component embeds a watermark by altering data samples of the media content in the spatial, temporal or some other domain (e.g., Fourier, Discrete Cosine or Wavelet transform domains). The reading component analyzes target content to detect whether a watermark is present. In applications where the watermark encodes information (e.g., a plural-bit message), the reader extracts this information from the detected watermark.
The present assignee's work in steganography, data hiding and digital watermarking is reflected, e.g., in U.S. Pat. Nos. 5,862,260, 6,408,082, 6,614,914, 6,947,571; and in published specifications WO 9953428 and WO 0007356 (corresponding to U.S. Pat. Nos. 6,449,377 and 6,345,104). A great many other approaches are familiar to those skilled in the art. The artisan is presumed to be familiar with the full range of literature concerning steganography, data hiding and digital watermarking. Each of the above patent documents is hereby incorporated by reference. One aspect of the disclosure is a watermark detector and embedder that are closely related to a particular geographical area.
For example, in one implementation, a method is provided including: determining a current geographic area; selecting a first digital watermark detection key that is associated with the current geographic area, a selected first digital watermark detection key being selected from a plurality of digital watermark detection keys; and controlling a digital watermark detector to employ the selected first digital watermark detection key to analyze a signal to obtain a digital watermark message there from, wherein the selected first digital watermark detection key corresponds to a particular digital watermark embedding key that is uniquely assigned to the geographic area.
In another implementation, a method is provided including, in a cell phone, determining a current geographic area of the cell phone; selecting a first digital watermark detector that is associated with the current geographic area, a selected first digital watermark detector being selected from a plurality of different digital watermark detectors; and controlling the cell phone to employ the selected first digital watermark detector to analyze a signal to obtain a digital watermark message there from, wherein the selected first digital watermark detector corresponds to a particular digital watermark embedder that is uniquely assigned to the geographic area.
In still another implementation, a cell phone is provided including: a radio-frequency transceiver; electronic processing circuitry; and memory. The memory includes executable instructions stored therein for processing by the electronic processing circuitry. The instructions include instructions to: determine a current geographic area of the cell phone; select a first digital watermark detector that is associated with the current geographic area, a selected first digital watermark detector being selected from a plurality of different digital watermark detectors; and control the cell phone to employ the selected first digital watermark detector to analyze a signal to obtain a digital watermark message there from. The selected first digital watermark detector corresponds to a particular digital watermark embedder that is uniquely assigned to the geographic area.
Still another implementation is a method including: receiving a signal from a cell phone; determining, based at least in part on the signal, whether the cell phone is physically located in a predetermined home area; and if not in the predetermined home area, communicating a machine-readable code detector to the cell phone for use as its primary machine-readable code detector to detect machine-readable code while outside of its predetermined home area.
Further aspects, implementations, features and advantages will become even more apparent with reference to the following detailed description and accompanying drawings.